MERC Team Uses Bacteria to Tackle an Energy Challenge

One of the oldest life forms on the
planet may be able to help solve some
very modern problems. Certain strains
of cyanobacteria are known to produce
hydrogen, so staff in the Milton Eisenhower
Research Center (MERC) are studying the
bacteria to evaluate their potential as a
clean source of hydrogen fuel.

“Using bacteria to produce hydrogen
could create a portable power source
for Department of Defense applications
and provide an alternative fuel option,
and one that would not increase greenhouse
gases because cyanobacteria
actually consume carbon dioxide,” says
Richard Potember, co-investigator on a
Science and Technology Business Area
Independent Research and Development
(IRAD) project studying the issue.
“I thought it would be exciting to use
an ancient life form—cyanobacteria
have been around 3.7 billion years—to provide a new energy source.”

But before they can plug bacteria
into fuel cells, team members must first
determine the best way to maximize
the organisms’ hydrogen output.

“Our major goal for this IRAD is
to get the bacteria onto a film, which
has been shown to increase
the amount of hydrogen they
produce,” says MERC chemist
and co-investigator Jennifer
Breidenich. “We’re basically
taking something that nature
has already done and
we’re incorporating it into
materials to increase the
efficiency.”

Cyanobacteria obtain
their energy through
photosynthesis, so
spreading them out
on a film exposes each organism to
more light than if the bacteria were
suspended in liquid. In a jar full of
bacteria, those in the middle of the
container receive less light than those
near the sides, and therefore make less
hydrogen.

This project is the first of its kind
under a recently signed memorandum
of agreement between APL and the
Savannah River National Laboratory, a
Department of Energy laboratory near Aiken,
SC. Researchers at Savannah River are
experts in cyanobacteria and storing
and processing hydrogen, while APL
brings materials science expertise to the
project.

Scientists at North Carolina State
University are also participating, developing
a method to attach the bacteria
to a latex film.

The MERC team is attaching the
cyanobacteria to a polyvinyl-alcohol
hydrogel. The hydrogel is a bit
thicker than latex but still less
than a millimeter deep. The
advantage is that it can
hold both water and the nutrients that
cyanobacteria need to thrive so they
can split hydrogen from the water’s
oxygen molecules.

Hydrogen is not the only gas produced
by the bacteria, so their output
would need to be filtered before going
into a fuel cell. Breidenich says the
team will work with Savannah River
scientists on different types of membranes
to separate and filter the bacteria’s
output.

It may even be possible to one day
remove the cyanobacteria from the process
entirely, says Potember. The MERC
team is exploring the idea of recreating
the chemical processes performed
by the cyanobacteria so that they would
not need to depend on the living cells
to produce hydrogen, which might be
more appealing for fuel cells in harsh
environments.

"Fuel cells and advanced battery
concepts are of extreme importance for
Department of Defense energy applications,"
says Victor McCrary, APL's Science and Technology Business Area Executive.
"We believe the niche for APL will
be in the applications where we can
produce energy and power storage for
special-operation missions that increase
mission persistence for small sensor
platforms. In addition, several business
areas have expressed interest in new
and innovative concepts to reduce size
and weight over current portable power
sources. This IRAD project represents
the business area’s interest in energy
and power management, and builds
on the MERC’s expertise in advanced
materials and nanotechnology."